Sectional or link shaft



July 31,1928. 1,678,709 W. SCHURMANN SECTIONAL 0R LINK SHAFT Filed July27, 1926 2 Sheets-Sheet 1 a E .1 8 J 5 5 8 5- l July 31, 1928; 1,678,709

. W. SCHURMANN SECTIONAL R LINK SHAFT Filed July 27, 1926 2 Sheets-Sheet2 Patented July 31, 1928.

WALTER SCI-I'URMANN, OF DUSSE LDORF, GERMANY.

SEGTIONAL OR LINK HAFT.

Application filed July 27, 1926, Serial No.

This invention has reference to sectional or link-shafts, and it isintended among other objects and advantages to provide shafts of thekind referred to 'bymeans of which a greater degree of rigidity andaccuracy may be obtained than'it was possible to arrive at inlink-shafts as heretofore constructed. "T he link shafts or sectionalshafts heretofore known, as far as I am aware are open to the objectionthat they possess only a compara-v tively small degree of movability,and that there is so much play and idle motion in the direction ofrotation in the joints as to pre elude smooth running without theoccurrence of erking and striking movements; and there is, moreover, theinconvenience that with a change of the direction of rotation the shaftswill extend or will be reduced in length.

Now, this invention, to be described herewith is adapted to overcomethese inconveniencies, and among other advantages it isparticularly,distinguished by the fact that it posseses a great degreeof flexibility, while making provision to avoid all possibilities ofidle motion in the direction of movement. In accordance with thisinvention the joints are constructed substantially on the principle ofthe universal joints or Cardan-joints and in such a manner that theindividual links, when revolved, will be moved without play or deadmotion.

The invention will be more fully described by reference to theaccompanying drawing, showing by way of exemplification one of thepossible embodiments of the principle of this invention. In the drawing:Figures 1 and 2 represent the sectional or linkshafts in two differentelevational views. Figure 3 is a cross section on the line 3-3 of Figure2. Figures 4 to 7 illustrate the assembling of the sections of theshaft. A somewhat modified construction is shown in. two different viewsin Figures 8 and 9, and Figures 10 to 12 illustrate the manner ofassembling the sections.

As will appear from the drawing (Figures 1 to 7) the individual links,1, 2, 3, 4 and so on may be made from punched out flat pieces ofmaterial and each link is provided at its ends with substantiallysemi-circular recesses or openings 5, and the fork-shaped ends arecomposed of inwardly curved or hawk- 125,227, and in Germany October 1,1925.

shaped jaws 6 having acutely beveled, outwardly diverging inner faces attheir free ends. In the openings 5 separate circular discs 8 withcrosswise arranged peripheral slots 7 are inserted, and upon these discsthe succeeding links are mounted which are disposed at right angle withrelation to the next preceding link. In this manner the sections of theshaft are assembled, so

as to produce a link-shaft with Cardan like or universal joints. Therecesses 7 of the discs 8 correspond exactly to the thickness of thematerial of the particular links, and by this meansidle movement in thejoints during the revolution of thelinks is avoided. The distance of thefork-like ends 6 of the links from each other governs the movability ofthe shaft, and, as shown for instance in Figures 1 and 2 of the drawing,the link 2 may be moved in a vertical plane through the angle withrelation to the link 3, and

simultaneously through the angle B in the.

horizontal plane. The said angles comprise each degrees, therebyresulting in a very high degree of movability of the shaft.

Figures 4-7 illustrate the assembling of the shaft. In the recess 5 ofthe link 1 a disc 8 is mounted by first inserting-the disc in thetransverse direction according to Figure 5, and then turning it aroundthrough 90 degrees, whereupon va second member 2 is pushed onto the disc8, as shown in Figure 7. This causes the ends 6 of the link or member 2to be somewhat spring actuatingly spread apart, which is made possibleby the slot 9. After the parts have been assembled, unintentionaldetaching of the same is no longer possible in view of the fact that inthe assembled position the links are only adapted to turn relatively toeach other through the angles a and [3 (Figures 1 and 2 The novelsectional or link-shaft according to this invention may be employed withor without a guide tube. WVhen a guide tubing is used the shaft is verysatisfactorily circularly guided within the guiding tube, and inasmuchas the shaft makes contact with the tubing at the narrow joints only,only very slight friction is produced. The operating point of the torqueis situated in a very favorable manner at the periphery of the shaft. Asa further important advanthe thickness and width of the fork-shaped leg13 of themembflri 10. WVhen assembling.

the parts the cross piece 14 is first positioned as inthe form ofconstruction first mentioned (Figure 5'), whereupon the second'memberisintroduced from above, the-recess12 allowing of the insertion of. theleg 13 (Figure 11). Thereupon the second member .10 may be turned intothe operative position. according to Figure 1 2. The assembling of theparts is therefore 'efi'ecte'd without. any spring-acting straining of..the fork shaped leg13."

While the invention has been described herein with reference to what areconsidered two preferred forms of embodiment, it

should beunderstoodthat itis not limited thereto, but it may findexpression in other embodiments and modifications, without therebydeviating from the scope and spirit of the invention, as particularlypointed out in the claimshereunto appended.

I clain' z 1. Aflexible shaft or coupling comprising at least two flatlinlr'plates having forked end portions and a nearly' circular openingbetween the arms of the forks, and a flat disk within the openings ofthe forked ends of the link plates and havin transverse notches in itsperiphery arrangedin working pairs; one pair of notches receiving thefork arms of one link plate and the other pair of notches receiving thefork arms of the other link plate.

2. A flexible shaft or coupling comprising. at least two flat linkplateshaving fork end portions and a nearly circular opening be tweenthe arms of the forks, the outer and inner surfaces of the armsextending on arcs, and a flat circu lar disk within the openings of theforked ends of the linkplates and having. transverse notches. in itsperiphery arranged in working pairs; one pair of notches receiving thefork arms v of one. link plate and the other pairofnotches.'receivinglthe. fork arms of. the other link. plate, the edgesofthe link plates being longitudinally. con

caved between its forkedfends', wherebyeach.

link plate is intermediately contractedi.

3-. A link shaft-comprising crossi-li-nkwise.

connected flat'llink members having. forked ends with circular recessesfor. .the lreception of a connecting member,and a connecting meniberformed-of .a flat. disk with cross-wise arranged cut-outsi for thereception of the forked ends offthe links. I l H 4. A flexible shaft. orcoupling comprising. a coupling disk having pairsv of peripheral.notches at right angles to each other, and flatl link plateshavingforked endsreceiving the disk and respectively 'engaging,ithe notchesaxial slot intersecting its forkedJend. and

: therein, one of said link plates having; an

rendering the jaws of said forked-end resilient for spring-apart and.:spring-reaction actions in engaging andmai'ntaining.engagement with thenotches in the. disk engaged thereby, Y i 7 In testimony WhereofI'aiiixmysignature.

WALTER son-tinnitus.

